Modified rosin esters and the process of making same



monomethallyl maleate, dicrotyl maleate, mono-,

Patented Apr. 16, 1946 I I n s MODIFIED BOSIN ES'I'EBS AND THE PROCESS MAKING-SAME John B. Bust West Grange, N. 1., assigninto Montclair ch Corporation, a corporation or New Jersey r Appliwtion April 14, 1944 Serial No. 531,117

20 s. (on. 260-27) The present invention relates to modified rosin tration only. After this preliminary reaction is esters which are particularly adapted for use in over the temperature is raised to 250 C. or higher coating compositions. in order to eflect further polymerization, and

It is an object of this invention to provide modincrease the softening point of the product to the iiied rosin esters which are hard and tough and desired degree. Although the above procedure is compatible with nitrocellulose. satisfactory and oiiers good control in the proc- It is an object of this invention to provide modless of the present invention, the ingredients may fled rosin esters which are soluble in drying oils be mixed and heated directly to 250 C. or higher,

and which may be made heat-convertible on to about 300 C. proper formulation, I may use very small amounts of unsaturated It is a further object to provide modified natester to modify the resin esters such as about ural resin esters which accelerate the bodying 0 I may use more, such as 3 Or more. of drying il When I use ester gum, I may use 10% of, for in- Another object of this invention is to make stance, diallyl maleate to obtain a hard resinhigh melting, tough, pale-colored modified rosin 5 having excellent pr p t es in varnishes and lacesters useful as components in varnishes. V q Us g ester gum as an example agai Another object of the invention is to make I have found that when more than about 25% of substantially neutral, heat hardenable derivatives dially maleato is used a t e reaction is carof rosin esters. ried to its ultimate, then gelled resins result Still further objects and advantages of the h h. are insoluble, or only sli h y soluble in present invention will appear from th more solvents but which may be swollen to some extent tailed description set forth below, it being underdepending upo t amount of combined a v stood that this more detailed description is given maleate. The greater the amount of diallyl by Way of illustration and explanation only, and maleate, the harder are the resins and the less not by way of limitation, since various changes swollen are the gell materials. therein may be made by those skilled in the art In another embodiment of the present i nwithout departing from the scope and spirit oi. tion a. mono-unsaturated ester, such as monoallyl maleate, is heated with a rosin ester such as the invention. The process of the present invention comprises lyoeryl dlabietate or other p y ri al hol reacting rosin esters, such as those consisting st formed from an ss of po yhyd o a coessentially of glyceryl abietate, pentaerythrityl ho], to give the interester, interreaction product. abietate, mannityl abietate and the like, with a In this way a substantially neutral interesterlfied unsaturated alcohol ester of an alpha unsatu- Product may be made which contains less unrated alpha beta dicarboxylic acid such as diallyl saturated al hol than does the diunsaturated maleate, monoallyl maleate'dimethallylmaleate, ester-modifi rosin e er. In some cases the latter procedure is preferred since only a monounsaturated ester is employed. Such monounsaturated esters are easily prepared by mixing molecularly equivalent amounts of unsaturated of fumaric, citraconic, itaconic, acetylene dicar- 40 alcohol and unsaturated dibasic acid anhydride boxylic acid and the like, instead of maleic acid and heating for a short time to obtain the acid 7 esters. The rosin ester is one which still contains ester. the characteristic unsaturation of abietic acid I have also found that it is possible to copolyor rosin acids. Mixed esters can also be used merize the products oi the present invention with such as rosin-phthalic glyceride. polymerizable compounds such as styrene, methyl It has been found possible to coreact the rosin methacrylate; ethyl acrylate, vinyl acetate, inester and allyl diester at a relatively low temdene, and the like. Thus I may first carry out perature of about 200-220 C. until a preliminary a preliminary reaction between, for instance, reaction is over. This preliminary reaction apester gum and diallyl maleate and'then copolypears to be in the form of a partial reaction of merize with, for instance, styrene. Such copolythe ally1 ester with rosin ester, followed by a par-. mer resins are very useful in making varnishes tial polymerization of this reaction product and with drying oils and making lacquers with nitrocopolymerization with part of the allyl ester. cellulose, or other cellulose derivative. I do not, however, wish to be limited by theory, The resins of the present invention are preferthe above statement being made by way of illusably made without polymerization catalysts.

crotyl maleate, dipropargyl maleate, monopropargyl maleate, dibutenyl maleate, monobutenyl maleate, and the like, or the above alcohol esters However, the use of catalysts speeds up initial polymerization if it is desired to effect such reaction and also accelerates the final polymerization.

The modified resins of the present invention may be put to a variety of uses, as for instance in formulations of lacquers with nitrocellulose, varnishes with drying oils, etc. It is a particular object of this invention to produce oil-reactive heat-advancing resins by the modification of rosin esters with unsaturated esters, capable of continued polymerization when they are heated with drying oils in the usual practice of making varnishes. The resins of the present invention may also be blended with other resins such as urea-formaldehyde resins, phenol-aldehyde resins, melamine-formaldehyde resins, vinyl resins,

methyl methacrylate resins, acrylate resins, cellulose derivatives, polyvinyl alcohol, vlnylidene chloride resins, and the like.

The following examples are given to illustrate the process and products of the present invention. All proportions are in parts by weight.

Example 1.-4500 parts of ester gum consisting essentially of glyceryl abietate and 500 parts of diallyl maleate were heated together in a reactor containing a mechanical stirrer, thermometer, and reflux condenser. The resin and allyl ester were heated to 200 C. and thereafter as follows:

200-220 C. for'2 hours 230-240 C. for 5 hours 240-260 C. for 3 hours 260-300 C. for 3 hours A light colored, brittle resin was obtained which was harder and tougher than ester gum. It possessed a ball and ring softening point of 114 C. and an acid number of 10.6.

Forty parts of a drying oil (e. g., a linseed oil product wherein a certain amount of conjugated unsaturation has been produced such as that known as Conjulin) was heated to 275 C. and 20 parts of the above resin was added. The resin dissolved and the temperature was held at 235-240 C. until a drop placed on a glass plate and cooled could be drawn out into a string15-18 inches long. The base was thinned with 60 parts of mineral spirits to which 0.5% Pb and 0.05% Co (as naphthenate) was added. The resulting varnish was clear and light-colored. It dried dustfree in 1 hour and hard in 8 hours. After 48 hours the film showed a Sward hardness of 43 and withstood immersion in water for 48 hours.

The resin'was also used in a lacquer of the following formula 2' Percent Nitrocellulose 8.33

Resin 25.00 Xylol .15.00 Butyl acetate l 30.00 Amyl acetate 16.67 Ethyl acetate 2.50 Octyl alcohol 2.50

The lacquer gave a clear film which after drying for 1 hour showed a Sward hardness of 11, and after 48 hours, 51. Ester gum used'in the same formula showed. a Sward hardness after 1 hour of '7 and after 48 hours, 40.

Allyl ester-modified ester gum resins such as the above are soluble in esters, ketones, hydrocar bons, chlorinated hydrocarbons, glycol ethers, nitropropane, and alcohols such as butanol; insoluble in ethyl alcohol and ethylene glycol.

Example 2.--4000 parts of ester gum and 1000 parts of diallyl maleate were heated together in a 200-220 C. for 2 hours 220-240 C. for 5 hours 240-260 C. for 3 hours This resin,-at room temperature, was light in color and in the latter stages of heating foamed considerably and was very viscous. The resin possessed a softening point of 118 C. and an acid number of 9.4.

The resin was completely saponified by heatin with concentrated sodiumhydroxide solution and the solution of the saponified material was acidifled with acetic acid. The precipitate was filtered and washed to remove all water-soluble substances and dried. The acid number was 158. On heating at 250 C. for 2 hours the acid number was 41.

Example 3.-3500 parts of ester gum and 1500 parts of diallyl maleate were heated together in a reactor equipped with a thermometer, condenser and a mechanical stirrer, to 200 C. over a period of 1 hour. Thereafter heating Was continued as follows:

200-220 c. for 2 hours 220-240 C. for 5 hours 240-260 C. for 1 hour During the last hour of heating this resin foamed considerably and the molten mass could be pulled into long strings. Additional heating at 240-260 C. of a duplicate formulation yielded an infusible, oil-insoluble resin which was only partially soluble in the usual solvents. The soluble resin possessed a softening point of 104 C. and an acid number of 8.5.

Example 4. parts of ester gum and 66.7 parts of diallyl maleate were heated together in a three-neck flask equipped with a thermometer, condenser, and a mechanical stirrer to 200 C. over a period of 1 hour. Thereafter heating was continued as follows:

200220 C. for 5 hours 220230 C. for 2 hours A pale-colored, hard resin was obtained. It possessed a softening point of 114 C. and an acid number of 5.9.

Example 5.- parts of pentaerythrityl abietate and 31.25 parts of diallyl maleate were heated together to 200 C. in 1 hour in a flask equipped with a thermometer, condenser and a mechanical stirrer. Thereafter heating was continued as follows:

200-230 C. for V2 hour 230 C. up to 260 C. for 9 /2 hours 200-220 c. for 3 hours 220.-250 C. for 4 hours An extremely light-colored, hard, brittle resin was obtained having a softening point of 118 C. and an acid number of 16.1.

Example 7. parts of ester gum and 60 asoaeca heating was continued as follows:

200 C.-220 C. 3hours 220 C.-230 C. 3% hours An extremely pale-colored resin was obtained.

It possessed a softening point of 119 C. and an acid number of 30.8. Example 8.160 parts of ester gum and 40 parts of diallyl chloromaleate were heated toather in a flask equipped with a thermometer, condenser, and stirrer. The reactants were heat.- ed to 200 C. in 1 hour. Thereafter heating was continued as follows:

200220 C. for 2 hours 220-240 C. for 2 hours 240-260 C for 6 hours A somewhat darker colored resin was obtained which possessed a softening point of 114 C-.jand an acid number of 34.4..

Example 9.--160 parts of ester gum and, 40 parts of diallyl itaconate: were heatedtogether in a flask equipped with; a condenser, thermometer,

and a stirrer. Thereactants were heated; to 200 C. in Lhour. Thereafter'heating'was continued as follows: 1

2009-220 C. for 2 hours 220 240 C. for 2 hours 240-260" C. for 6 hours A clear, fairly light-colored resin was obtained which possessed. a. softening point of 110 C. and

an acid number of 10.

Example 10..--160 partsof ester gum and 40 parts: of diallyl citraconate were heated together in a three-neck flask equipped with a stirrer, condenser, and thermometer. The reactants were heated to 200 C. over a period of 1 hour and thereafter as follows:

200-22o" c. 2 hours 240-260 c. .6 hours A hard, brittle resin of fair colorwas obtained. The resin possessed an acid number of19.4\and a softening point of 112 C.

The following examples are used to illustrate another process of preparing the resin or the present invention. The process consists of esterifying a rosin polyhydroxy compound containing one or more free hydroxyl groups, then completeing esterification with, for instance, a monoallyl maleate ester.

Example 11.711.6 parts of rosin (2 moles) and 95.15 parts of glycerol (1 mole) were heated together at 234-255 C. for 2 hours. 613.8.

moles) and 66.5 parts of pentaerythritol (A a mole) were heated together at 150-250 C. for 2 hours. 183.5 parts of the above rosin pentaerythritol ester and 29.25 parts of monoallyl maleate were heated together slowly to 200 C. and heated thereafter as follows:

200-230 C. for 1% hours 230-250 C. for 2 hours therefore, soluble resinous interreaction products An extremely light-colored resin was obtained which possessed a softening point of 126 C. and an acid number of 48.

Example 13.-270 parts of rosin (.9 mole): and

36.3 parts of trihydroxymethyl-amino-methane (.5 mole) were heated together at 200-250- 0..

for 2 hours. 181.2 parts of the above rosin ester and 29.25 parts of monoallyl maleate were heated together at 200-250 C. for 1% hours. A hard, brittle, light-colored resin was obtained which possessed an acid number of 18.5 and a softening point of 128 0.

Example 14.200 parts of rosin (.66 mole) and 30.'! parts of glycerol (.33 mole) were heated together at 200-260 C. over a period of 4 hours. 56.6 parts of monoallyl citraconate were then addedand heating continued at 200-240 C. for 6 hours. A pale-colored, brittle, resin was obtained with 15 parts of diallyl maleate at 200 220 Ci.

for 1 hour, then at 280-290 C. for '1 hour- The mixture slowly increased in viscosity and finally set up to an infusible gel. The gel was insoluble in a solvent composed of acetone, benzene. ethyl acetate and isopropanol. The resin swelled and broke up but did not dissolve.

Example 17.-187 .6 parts of ester gum, 9.2 parts of glycerol and 51 parts of monomethallyl maleate were mixed and heated at 200 C. for 1 hour,

then at 200-250 C. until a light-colored, hard,

tough resin was secured. This resin possessed a softening point of 103 C. and anacid number of 27.2.

It has been proposed to heat estergum and diallyl maleate in the presence of benzoyl peroxide as a polymerization catalyst. For example, when 75 parts diallyl maleate, 25 parts ester gum and 10 parts benzoyl peroxide are mixed and the solution poured as a film and heated 1 hour at 250 F., it forms a hard, non-thermoplastic film. Likewise, when the solution is heated in a flask at 250 F. it rapidly forms a spongy mass. This is not a reaction product of ester gum and allyl maleate, but, as stated, it consists of ester sum dispersed in polymerized diallyl maleate since unchanged estergum can be extracted from the mass by treating it with an ester gum solvent (e. g., benzene). which leaves polymerized diallylmaleate ,undissolved. No interreaction product of diallyl maleate and ester gum is formed under these conditions since the allyl maleate is polymerized and the ester gum remains distributed throughout the mass. W

The presence of unchanged rosin ester in a composition is easily determined by the Starch-Morawski test and in this connection it may be noted that a gelled product obtained by polymerizing diallyl maleate in the presence of ester gum shows a positive test for free rosin ester, whereas an interreaction product of ester gum and diallyl maleate shows a negative test.

The products of the present invention comprise;

of a rosin or abietic acid ester, preferably a polyydric alcohol ester. andan unsaturated dicarboxylic acid allyl ester. The process consists in heatingthe rosin ester andallyl ester under conditions to obtain reaction between the two (i. e.,

I at between 200 0. and about 300 0.), followed by further heating to cause polymerization of the reaction product, and polymerization and copolymerization of the allyl ester in those cases where an excess of allyl maleate is present. They allyl ester is an ester oi. allyl alcohol (or a substituted allyl alcohol such as methaliyl, chloroaily'i, crotonyl, etc.) and an alpha-beta unsaturated dicarboxylic acid, that. is, an unsaturated dicarboxylic acid wherein the carboxyl groups are'attached to adjacent carbon atoms and at least one is connected to an unsaturated carbon atom.

The products of this invention when hydrolyzed yield a water-insoluble product, the acid number of which is lowered on heating. That is, whenthe resinous product .is saponifled by alkali and the saponification solution acidified, a water-insoluble hydrolytic product is obtained which apparently consists of acids and hydroxy acids, such bodies being a result of an addition reaction between the double bonds of the abieticpart of the rosin ester and the double bonds of the allyl ester, during the production of the resin. Heating of the water-insoluble hydrolytic product causes esteriflcation and lowering of the acid number. The resins herein described are therefore characterized in that the water-insoluble hydrolytic products thereof, when heated. are reduced in acid number. I

I claim:

l. The process of making a soluble resinous reaction product which comprises heating, at between 200 and about 300 C., an abietic acid ester and an allyl ester of an alpha unsaturated alpha beta dicarboxylic acid.

2. The process-oi making a soluble resinous retween 200: C. and about 300 0., a-rosin-polyhydric alcohol ester and an ally] ester of an alpha unsaturated alpha beta dicarboxylic acid.

3. The process of making a soluble resinous reaction product which comprises heating, at between 200 C. and about 300 0., a rosin polyhydric alcohol ester formed from equivalent amounts of rosin acids and polyhydrlc alcohol, and a diallyl ester of an alpha unsaturated alpha beta dicarboxylic acid.

4. The process of making a soluble, substantially. neutral, resinous reaction product which comprises heating, at between 200 (Land about 300 C.. a rosin-polyhydric alcohol ester formed from an excess of polyhydric alcohol, and a monoallyl alcohol ester of an alpha unsaturated alpha beta dicarboxylic acid.

5. The processor claim 3 where the allyl ester is diallyl maleate.

6. The process of claim 3 where the allyl ester is diallyl fumarate.

7. The process of claim 4 where the allyl ester is monoallyl maleate.

8. The process or making a soluble resinous reaction product which comprisesheating rosin-'- glyceride anddiallyl maleate at between-200 and .300 C. 9. The process of making ,a soluble resinous 5 reaction'product which comprises heating rosin-- 'glyceride and di-allyl Ifumarate at between 200 and 300". v 10.- The process of making a soluble resinous *1 reaction product which comprises heatingglyc- 1 erol diabietate and monoallylmaleate at'between 200 and 300 C.

11. A modified rosin ester adapted for use in coating compositions which comprises a heatreaction product of a rosin ester containing conjugated double bonds in the abietateportion and an allyl ester of an alpha unsaturated alpha beta dicarboxylic acid, said product yielding a water-insoluble hydrolytic product being obtained by heating the rosinester and the allyl ester at between 200 and 300 C. and, after saponification whose 'acid number: is lowered 14. A soluble resinous composition comprising a reaction product obtained by heating a rosinpolyhydric alcohol estr formed with an excess of p lyhydric alcohol, and a monoallyl esterot an alpha unsaturated alpha beta dicarboxyiic acid at/between 200 and 300C.

40 15. A soluble resinous composition comprising the heat-reaction product, at between 200 and 300 C., of a rosin-.polyhydric alcohol ester and diallyl maleate.

16. A soluble resinous composition comprising the heat-reaction product, at between 200 and 300 0., of a rosin-polyhydric alcohol ester and dially fumarate.

17. A soluble resinous composition comprising the heat-reaction product, at between 200 and 300 C., of rosin-glyceride anddiallyl maleate.

-19. A soluble resinous composition comprising the heat-reaction product, at between 200 and 300 C., of rosin-glyceride and diallyl tumarate. 20. A soluble resinous composition comprising the heat-reaction product, at.between 200 and maleate.

JOHN B. RUST.

' and the allyl ester at between 200 and 300 C, and an Certificate of Correction Patent No. 2,398,668. a April 16, 1946.

JOHN B. RUST It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 4, second column, lines 18, 19 and 20, claim 11, strike out the words being obtained b heating the rosin ester d insert the same before yielding, line 17, same claim; and that the said Letters Patent shouldbe read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 2d day of July, A. D. 1946.

[sun] LESLIE FRAZER,

First Assistant Commissioner of Patents; 

